Preparation of alkyl aminosulfides



Patented Sept. 21, 1954 PREPARATION OF ALKYL AMINOSULFIDES John E. Maham' Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware NoDrawing. Application December 3, 1948,

' Serial No. 63,433

Claims. 1

This invention relates to new and novel compositions and to their preparation. In another aspect this invention relates to alkyl aminoalkyl sulfides and alkyl aminocycloalkyl sulfides. Another aspect of this invention relates to a process for the production of alkyl aminoalk-yl sulfides.

An object of this invention isto provide alkyl aminocycloalkyl sulfides as new compositions.

Another object is to provide a process for the production of alkyl aminoalkyl sulfides and alkyl aminocycloalkyl sulfides.

Another object is to provide a process wherein an amino sulfuric acid is reacted with an aliphatic mercaptan to produce a corresponding sulfide.

Other objects will be apparent; to those skilled in the art, from the accompanying discussion and disclosure.

' In accordance with my invention 'alkylaminocycloalkyl sulfides and alkyl aminoalkyl sulfides are prepared by the interaction of an aliphatic mercaptan with a molar equivalent of a selected amino sulfuric acid in the presence of an alkaline-reacting agent. The following equation is illustrative of my invention.

R Alkaline-reacting agent RSH HOZSO RIN RI! Aliphaptic Amino sulfuric mercaptan acid H2804 RSR-N \RI/I Alkyl amino sulfide In each of the above compounds, R is selected from the group consisting of primary, secondary and tertiary alkyl radicals containing not more than 16 carbon atoms, R is selected from the group consisting of alkylene, cyclopentylene, and cyclohexylene radicals containing not more than 10 carbon atoms, R" is selected from the group consisting of hydrogen, alkyl, aryl and aralkyl radicals, R is selected from the group consisting of hydrogen alkyl, aryl and "aralkyl radicals, and R" and R' may form a heterocyclic ring together with the nitrogen, the sum of the number of carbon atoms in R" and R' not exceeding 10. The alkyl amino sulfides produced in accordance with my invention may be converted to their quaternary salts which are important materials in the manufacture of detergents and surface active agents. In view of the tlu'oether linkage present, these compounds may be converted by oxidation to amino sulfoxides and sulfones.

Among the aliphatic mercaptans that maybe employed in the practice of my invention are, propylmercaptan, n-butylmercaptan, isobu-tylmercaptan, tertiary butylmercaptan, n-pentylmercaptan, isohexylmercaptan, iso-octylmercaptan, n-decylmercaptan, n-dodecylmercaptan, tert-dodecylmercaptan, n-hexadecylmercaptan, and the like.

Amino sulfuric acids that may be employed herein include various types depending on the specific composition being prepared. For example, in the production of alkyl primary aminoalkyl sulfides, a primary aminosulfuric acid such as Z-amino-l, l-dimethyl-ethyl sulfuric acid may be employed; in the production of an alkyl secondary amino alkyl sulfide, an N-alkyl aminoalkyl sulfuric acid such as N-methyl-Z-aminoethyl sulfuric acid may be employed; and in the production of an alkyl tertiary aminoalkyl sulfide an N,N-di-alkyl aminoalkyl sulfuric acid such as N,N dimethyl-2-amino ethyl sulfuric acid may be employed. In the production of alkyl aminocycloalkyl sulfides such as an alkyl primary aminocyc'loalkyl sulfide, an amino sulfuric acid such as 4-aminocyclohexyl sulfuric acid or 3-aminocyclopentyl sulfuric acid may be employed; in theproductionof an alkyl secondary aminocycloalkyl sulfide an amino sulfuric acid such as N-methyl 4-'-aminocyclohexyl sulfuric acid or N-ethyl Z-aminocyclopentyl sulfuric acid may be employed; and in the production-of an alkyl tertiary-aminocycloalkyl sulfide, an amino sulfuric acid such as N,N-dimethyl 3-aminocyclopentyl sulfuric acid or N,N+dimethyl ii-ammocyclohexyl sulfuric acid may be employed. Among the amino alkyl sulfuric acids that may be used in the preparation of an alkyl amino sulfide wherein the R"s form a ring of which nitrogen is a part, are, morpholinyl sulfuric acids such as morpholinyl methyl sulfuric acid,

Hz H: 0-0 H morpholinyl 2-cvyclopentylsulfuric acid,

and morpholinyl 4-cyclohexyl-sulfuricacid,

pyrrolidyl sulfuric acids such as pyrrolidyl methyl sulfuric acid,

H2 HzC-C HzC-C pyrrolidyl 3-cyclopentyl sulfuric acid,

H 112 H I N--0-0-0S02H 0-0 0--0 H2 H1 H2 H2 and pyrrolidyl 3-cyclohexyl sulfuric acid,

H2 H2 H2 H2 0-0 H 0-0 H2 I/ \l /NO /0 0-0 0-0-osoi11 Hz H2 H2 H and piperidyl sulfuric acids such as piperidyl ethyl sulfuric acid,

The alkyl aminocycloalkyl sulfides as described herein above are new compositions.

Alkaline-reacting agents referred to herein preferably include the alkali metal oxides and hydroxides, and the alkaline salts of the alkali metals, such as sodium carbonate. Alternately, alkaline earth metal oxides and hydroxides, and mixtures of alkali metal and alkaline earth metal oxides or hydroxides may be employed as alkaline-reacting agents, in the practice of my invention. At least one mole, preferably two moles, of alkaline-reacting agent are employed per mole of total mercaptan and amino sulfuric acid reactants. Sometimes 3 moles or more, of alkalinereacting agent per mole of total reactants may be advantageously employed. Although the general equation presented above shows sulfuric acid as one of the reaction products, it immediately reacts with the alkaline-reacting agent to form the corresponding salt.

In a preferred embodiment of my invention, a selected aliphatic mercaptan is co-mingled with a selected aqueous amino sulfuric acid, in a mole ratio of mercaptan to the acid usually within the limits of from 1:1 to 1:3, in the presence of an alkaline-reacting agent of the type already described, preferably aqueous sodium hydroxide, and the resulting reaction mixture is heated for a period of from about 2 to 48 hours with constant agitation. The reaction may be conveniently conducted under reflux. At the end of the reaction period, the reactants are cooled and the crude product is removed and purified.

In another embodiment of my invention the aliphatic mercaptan reactant is comingled with the amino sulfuric acid reactant, in a mole ratio of mercaptan to the acid usually within the limits of 1:1 to 1:3, in the presence of an alkalinereacting agent of the type already described; the resulting admixture is then heated for a period of from 10-15 hours at a temperature in the range IOU- C. and thereafter for a period of from 20 to 30 hours at a temperature higher than 110 C. and not above C.

I prefer usually to conduct the product-fortning step at a temperature in the range of from 50 to 150 C. for a period usually of from 1 to 48 hours, although in some instances shorter or longer reaction times may be advantageously employed. I may employ pressures varying from subatmospheric to superatmospheric, usually in the range of from atmospheric pressure to 250 p. s. i. g. After the desired reaction period, the reaction mixture is cooled, and may be admixed with excess 50 per cent alkali at a temperature below from 10 to 15 C., preferably ice temperature, to cause dissolution of any sulfide product and to dissolve any unreacted mercaptan and/or acid. The product phase is an oil, and may be readily separated from the aqueous layer and dried in any suitable manner.

As already stated, the excess 50 per cent aqueous alkali hydroxide is employed as a means of effecting separation of the oil product from the water solution. In this step of my process from 1 to 2 moles of alkali, in 50 per cent aqueous solution, per mole of sulfide product in the reaction mixture may be advantageously employed. However, other suitable means of separating the sulfide product from the reaction mixture, such as solvent extraction, may be utilized. Ether may be advantageously employed as a solvent, and the extract may be distilled to yield a purifled sulfide product. In some instances high molecular weight product may be formed which is non-soluble in Water solution, in which case treatment with aqueous alkali reagent would be unnecessary. Other means than the use of aqueous alkali, known to those skilled in the art, for effecting such a separation of sulfide product from the reaction mixture may be used in the practice of this invention.

Although the use of an aqueous reaction medium is advantageous for carrying out the process of my invention, other solvents, particularly an alcohol, may be employed. In those cases wherein the non-aqueous medium is employed, use of the metal mercaptide in place of the mercaptan may be advantageous.

Although the process of this invention is described with particular reference to batch-wise operation, it may be carried out in a continuous operation when desired. Such an embodiment of the process presents definite advantages in large scale operation and is within the scope of this invention.

My invention is illustrated by the following examples. The reactants, their proportions, and other specific ingredients are presented as being typical and should not be construed to limit the invention unduly.

Example 1 A run was made wherein tert-butyl mercaptan, 2-aminoethyl sulfuric acid, and 10 per cent aqueous sodium hydroxide were charged to a closed reactor in a respective 1:1:2 mole ratio. The temperature was then raised to 107 C. and the reaction mixture was maintained at that level for 6 hours with continuous agitation. The

reaction mixture, after cooling, was treated. With] captan. The product waspurified by extraction with ether andrdistilled under vacuum. A. yield of 51.9mole 138127 08111; of izeaminoethyletertebutyl sulfide/was obtained? A .redistilled portion of the 2 aminoethyl=tert-butyl sulfide 5 product, had 1 a boiling... point .of 643-1553? 0. andgairefractive index, ri ,of 1.4787. The: determined ,molec ulariweight ,Of :thE JPIOdUCtIJWaS ;13313., The by:

drochloride of this product had a melting point Example 2 A run was made wherein -tert-octyl mercaptan prepared by reactingamixture of .octenes with hydrogen sulfide :in the (presence of an alumina type catalyst ,;2- aminoethy1 sulfuric acid, and

pe cent aqueous sodium hydroxide were charged 1 to a closed reactor in arespective 1:1:2 mole ratio. The temperature was then raised to 104 C. and maintained. between l04and 110 C. for hours with continuous agitation Th temperature was then raised tc.149f C. and maintained at. that level for an additional 23hours with agitation. The sulfideproduct wastpurified as in,

Example 1. Aredistilled portion of the 2-aminoethyl-tert-octyl sulfideproduct obtained had a boiling point of 114-115" C. anda refractive index, a of 1.4888. The determined molecular weight .of; the, product :was.-:.l95.l, The :hydrochloride of thisrproduct had a melting point of 182186 C.

Example 3 i-aminocyclohexyltert-butyl sulfide is prepared by, followin the"procedure described in Example 1, except that l-aminocyclohexyl sulfuric acid is used=-in place of Z-aminoethyl sulfuric acid; The yield, after'purification by distillationunder vacuum, is 38 mole; per cent. The molecular weight of the product is 195.

Example 4t.

Z-aminoethyl-n-propyl, sulfide V. is prepared by reacting 1 mole of n-propyl mercaptan, 1 mole of 2-aminoethy1 sulfuric acid and 2 moles of sodium hydroxide in 10 per cent aqueous solution, the reaction being carried out according to the method ofExample 1. The yield after purification by distillation in vacuo is 46 mole per cent. The 2-aminoethy1-n-propy1 sulfide product is a colorless oil boiling at 84-87 C. under mm. pressure; the density at 25 C. is 0.9294 and the index of refraction, n is 1.4832. On analysis the sulfur content is found to be 26.8.

As will be evident to those skilled in the art, various modifications of this invention can be made, or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the claims.

Iclaim:

1. A process for the preparation of an alkyl amino sulfide having a composition in accordance with the following structural formula wherein R is an alkyl radical having not more than 16 carbon atoms, wherein R is selected from the group consisting of alkylene, cyclopentylene and cyclohexylene radicals, said alkyleneicontainingsnot morethan: 10 carbon atoms, wherein RV and R are each selected from the groupconsisting of hydrogen, .alkyl, aryl, and

aralkyl: radicals, and. radicals whichutogether with each: other, andxsaid nitrogen form. a hetero cyclic ring, and the sumiofltheztotal number of carbonatomsin R. andRa" isnotgreater than 10,: saidprocess comprising. .reactingone molecular. equivalent ;of (an. .aliphatic.mercaptan having the structural formula R'--S-V-H, wherein R is as above .:.described,'. with one molecular equivalent oft-a substitutedcsulfuridacid having the structural formula HQSOrRI N wherein R, R", and R/ are asabove described, in the presence of an alkaline-reacting agent selected from the group consisting of alkali metal oxides, alkalimetal hydroxides and alkaline salts ofan alkali metal, heating the resulting admireture for a period offr'om IOA-Sh'ours at-a ternperature in therange of IOU- C; and thereafter for a periodof 30 hours at a temperaturehigher :than 110 C. but not: above C. then adding tosthe resulting reaction mixture, maintained at altemperature below 15C., from one to two moles of an alkali'metal hydroxide, in" aqueous solutionin a concentration of at least 50-weightper cent, per mole of sulfide product therein, whereby alkyl amino sulfide product is obtained. as a separate oil phase free from unreacted imercaptan and acid reactants, and recovering said oil phase as a purified product of the process. i

2. The process of claiml wherein said mercaptan is tert-butyl mercaptan. andwherein said sulfuric acid is Z-aminoethyl sulfuric acid.

3. The process of claim 1 wherein said mercaptan is tert-butyl mercaptan and'wherein said sulfuric acid is 4-aminocyclohexy1 sulfuric acid.

4. In a process for the production of an alkyl amino sulfide by reacting anzaliphatic mercaptan withp-an aminorsulf-uric acid in the presence of an alkaline reacting agent, saidalkyl amino sulfide being characterized by the structural: formula wherein R is an alkyl radical having not more than 16 carbon atoms, R is selected from the group consisting of alkylene, cyclopentylene and cyclohexylene radicals, said alkylene containing not mor than 10 carbon atoms and R" and R are each selected from the group consisting of hydrogen, alkyl, aryl, and aralkyl radicals and radicals which together with each other and said nitrogen form a heterocyclic ring, the sum of the total number of carbon atoms in R" and R being not greater than 10, said mercaptan being characterized by the structural formula R-SH, wherein R is as above described and said amino sulfuric acid being characterized by the structural formula RI! HOSOaR-N RIII wherein R, R" and R' are as above described, the improvement comprising maintaining ,the resulting reaction mixture at a temperature below 15 C. and adding thereto from 1 to 2 moles of alkali metal hydroxide in aqueous solution in a concentration of at least 50 weight per cent, per mole of said sulfide product therein, whereby alkyl amino sulfide product is obtained as a separate oil phase free from unreacted mercaptan and acid reactants, and recovering said oil phase as a purified product of the process.

5. The improvement of claim 4 wherein said reaction mixture is maintained at ice temperature during the addition thereto of said aqueous alkali metal hydroxide.

6. The improvement of claim wherein said alkali metal hydroxide is sodium hydroxide.

'7. In a process for the production of 4-aminocyclohexyl-tert-butyl sulfide by reacting tertbutyl mercaptan with 4-aminocyclohexyl sulfuric acid in the presence of an alkaline reacting agent at a temperature within the range of 50 to 150 C., the improvement comprising maintainin the resulting reaction mixture at a temperature below C. and adding thereto from 1 to 2 moles of an alkali metal hydroxide in aqueous solution in a concentration of at least 50 weight per cent, per mole of 4-aminocyclohexyl-tert-buty1 sulfide product therein, whereby 4-aminocyclohexyltert-butyl sulfide product is obta ned as a separate oil phase free from unreacted mercaptan and acid reactants, and recovering said oil phase as a purified product of the process.

8. In a process for the production of 2-amino ethyl tert-butyl sulfide by reacting tert-butyl mercaptan with 2-aminoethyl sulfuric acid in the presence of an alkaline reacting agent at a temperature within the range of 50 to 150 C, the improvement comprising maintaining the resulting reaction mixture at a temperature below 15 C. and adding thereto from 1 to 2 moles of an alkali metal hydroxide in aqueous solution in a concentration of at least 50 weight per cent, per mole of 2 aminoethyl-tert-butyl sulfide product therein, whereby Z-aminoethyl-tert-butyl sulfide product is obtained as a separate oil phase free from unreacted mercaptan and acid react ants, and recovering said oil phase as a purified product of the process.

9. In a process for the production of 2-aminoethyl-tert-octyl sulfide by reacting tert-octyl mercaptan with Z-aminoethyl sulfuric acid in the presence of an alkaline reacting agent at a temperature within the range to 150 C., the improvement comprising maintaining the resulting reaction mixture at a temperature below 15 C. and adding thereto from 1 to 2 moles of an alkali metal hydroxide in aqueous solution in a concentration of at least 50 weight per cent, per mole of 2-aminoethyl-tert-octyl sulfide product therein, whereby Z-aminoethyl-tert-octyl sulfide product is obtained as a separate oil phase free from unreacted mercaptan and acidreactants, and

recovering said oil phase as a purified product of the process.

10. A process for the manufacture of Z-aminoethyl-tert-octyl sulfide comprising admixing tertoctyl mercaptan with Z-aminoethyl sulfuric acid in a mole ratio thereto within the limits of 1:1 to 1:3, heating the resulting admixture in the presence of aqueous sodium hydroxide for a period of from 1015 hours at a temperature in the range of -110 C. and thereafter for a period of from 20-30 hours at a temperature higher than C. and not above 0., adding to the resulting reaction mixture from one to two mols of an alkali metal hydroxide in aqueous solution per mol of 2-aminoethyl-tert-octyl sulfide therein, whereby a separate oil phase comprising said Z-aminoethyl-tert-octyl sulfide is formed and is free from unreacted mercaptan and acid, and recovering said separated oil phase as a product of the process.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,050,169 Elbel Aug. 4, 1936 2,282,? 10 Dietrich May 12, 1942 2,304,623 Berchet Dec. 8, 1942 FOREIGN PATENTS Number Country Date 497,939 Great Britain Dec. 28, 1938 OTHER REFERENCES Suter, Organic Chemistry of Sulfur, J. Wiley, Inc., New York (1941) page 31. 

1. A PROCESS FOR THE PREPARATION OF AN ALKYL AMINO SULFIDE HAVING A COMPOSITION IN ACCORDANCE WITH THE FOLLOWING STRUCTURAL FORMULA 